SDL the following Part 2

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1 SDL the following Part 2 TMSP Stéphane Maag

2 Ready?

3 Objectives This course intends to make the participants discover: Structures Structural types Packages PID Procedures MacroDefinitions ASN.1 - Z.105

4 Remote Variables EXPORT-IMPORT: to get the value of a variable of another process (implicit signals) In a block or system

5 Definition of Structure Structure with Fields NEWTYPE Product STRUCT reference CHARSTRING; price REAL; quantity INTEGER; ENDNEWTYPE Product; The field types may be some structures

6 Use of Structure DCL prod Product; prod!price := 21.0 Prod := (. ball,20.0,3.) prod!reference := Super new ball assignment Modify by accessing the fields

7 Array Type Type of the index (integer) NEWTYPE Product_T ARRAY (Index_T,Product); ENDNEWTYPE; DCL prod_set Product_T; DCL prod Product; Initialization Modify Extract prod_set := (. (. ball,20.0,3.).) prod_set(1) := prod prod := prod_set(3) Indexes are integer

8 Process: Active Class SDL allows to generate process instances: They are active objects Perform their own actions Manage their own data Several possible instances may run in parallel. To represent them:

9 Structural Types and Instances Block type or Process type General description to reuse later Allows to generate many block or process instances Define the content of all instances We may define one instance or set of instances USER firstuser: USER Users(10): USER Block type A set of 10 instances of USER

10 Structural Types in ObjectGEODE system type process block type process type system

11 Why Block and Process type? They are defined once and used many times a defined block may then be used in different systems to define only once the content of several processes that run in different blocks structural types and instances available for systems, blocks and processes

12 Gates for structural types Structural types need gates Definition of process types gates define, with channels, the signals sent and/or received Instances are connected by channels through gates Use of process types

13 Examples of instantiations

14 Where to use structural types? In package: a set of types Structural types (block types, process types, ) Signals and lists Constants Data types A package allows to reuse types in several models.

15 Package example PR format

16 Package example

17 Dynamic Creation of Processes Process instance may dynamically creates instance of process in the same block. dynamic creation Block Industry Enterprise(1,1) Agency(0,Max) 1 and infinite by default

18 How to dynamically create processes The CREATE request provokes the immediate creation of the process. The created processes may carry parameters given by the creator. Process Enterprise idle new_one The new instance has its own new PID CREATE request Agency(nbr,name)

19 Process parameters Interval for the number of possible created instances PROCESS Agency(0,Max) FPAR nbr integer, name charstring actual parameters Formal parameters Agency(12,myagency) We may kill the processes

20 Process IDentification The PID is the unique identifier of each instance of process. Remember PID is a predefined type! The PID cannot be modified The PID type has one predefined constant: NULL PIDs are used for communication in case of many possible receivers. Client/server, mobile topologies (broadcast), signals that are both sent and received,...

21 Predefined PID expressions SELF: PID of the process itself OFFSPRING: last process instance created by itself. If none was created then OFFSPRING is NULL PARENT: PID of parent process. If SELF was not dynamically created, then PARENT is NULL SENDER: PID of the process that has sent the last consumed signal by SELF. If no consumed signal the SENDER is NULL

22 Process destination for Output S1 [TO process destination] [VIA path] S1 No destination specified unique dest. or non-det. choice VIA TO Process name PID channel or gate ALL c1,c2,c3 Multicast, one message for each route

23 Example of PID use sender s PID

24 Procedures Use to factorize and parameterize actions Encapsulation, abstraction Allow to reduce the EFSM size Executed in their owning process

the one of the process) Signals are sent to process only It may have local

25 Procedure definition It is described like process, using EFSM It is executed using the queue of its own process It does not have any PID (even the one of the process) Signals are sent to process only It may have local variables It can be defined at process, block or system level No Stop in a procedure

26 Procedure parameters Introduced by FPAR and IN or IN/OUT: FPAR: parameters of the procedure IN/OUT: IN: by reference it means that the parameter may be modified by value it means that the caller may not see the changes by default the parameter are IN.

27 Procedure Example Procedure declaration

28 Procedures as classic functions They may be called as classic functions in expressions: allows to return explicit values. x:=5* CALL Incr10(x) a value return

29 MacroDefinition The Macros allow to treat the repetition of code, a description, a behavior that is often repeated, Used only within processes or procedures, May have formal parameter, it is necessary to transmit them. Call of a macro Macro inlet symbol Macro outlet symbol

30 Macrodefinition Example Formal parameters inlet outlet

31 ASN.1 and SDL Z.105: Inclusion of ASN.1 in SDL Standard: ASN.1 is widely used in standards and can be part of the requirements Technically, ASN.1 allows to focus only on data: values, set of values,

32 Use of ASN.1 in Z.105 ASN.1 declarations located in same box than SDL ones, ASN.1 and SDL declaration may be mixed, Z.105 is not case-sensitive, hyphens ( - ) cannot be used.

33 ASN.1 predefined types INTEGER == INTEGER BOOLEAN == BOOLEAN REAL == REAL CHARSTRING == IA5String

34 SDL ASN.1 NEWTYPE colors LITERALS red, blue,black, yellow, white; ENDNEWTYPE colors; colors ::= ENUMERATED {red, blue,black, yellow, white}; SYNONYM clearcolor colors = white; clearcolor colors ::= white;

35 Composite types in ASN.1: Sequence types (Structure in SDL) NEWTYPE T_Seq STRUCT a BOOLEAN; b CHARSTRING OPTIONAL; c INTEGER DEFAULT 5; ENDNEWTYPE T_Seq; assignment T_Seq ::= SEQUENCE { a BOOLEAN, b IA5String OPTIONAL, c INTEGER DEFAULT 5}; s1 T_Seq ::= { a TRUE, b OK, c 12}; s2 T_Seq ::= { a FALSE, c 23}; s3 T_Seq ::= {a TRUE};

36 Sequence Example Process proc1 T_Seq ::= SEQUENCE { a BOOLEAN, b IA5String OPTIONAL, c INTEGER DEFAULT 5}; DCL var1, var2 T_Seq; idle idle obt(var1) b!present(var1) ( TRUE ) var1!a:=true ( FALSE ) var2:={a FALSE}

37 Composite types in ASN.1: CHOICE types Process proc1 T_Ch ::= CHOICE { a BOOLEAN, b IA5String, c INTEGER}; idle idle obt(var11) DCL var11, var12 T_Ch; var11!present ( a ) ( b ) ( c ) var12!present:=a var11:= {b: NOTOK } var11:= {a: FALSE}

38 CONCLUSION Think to use structural types for reusability Process ID Readability with procedure and macrodefinitions CHOICE in ASN.1

39 Exercises Specify a process that receives a message ATM_req containing a data atm_req as a structure (quantity, ticket) where quantity is an integer and ticket is an optional character. This process sends the output OK if ticket is received or NOK if not.

58 Building an Application

Chapter 58 Building an Application This chapter describes how you can use the Cadvanced SDL to C Compiler to generate applications and especially how to design the environment functions. These functions